Elastomers, process for preparation, and uses thereof

ABSTRACT

Elastomeric interpolymers comprising at least two, or more, cyclic olefin monomers that are prepared by ring opening metathesis polymerization, and that are characterized by having no crystallinity, a glass transition temperature (Tg) of less than −80° C., and a number average molecular weight (Mn) of at least 40 kg/mole, and functionalized products thereof. A ring opening metathesis polymerization process for producing the elastomeric interpolymers having no crystallinity. Uses of the elastomeric interpolymers in applications such as rubber compounds, tires, and the like. Cores of golf balls that are prepared by using metathesis polymerization produced elastomeric interpolymers having 0 to about 30% crystallinity.

This application claims the priority of Provisional U.S. PatentApplication Ser. No. 60/852,219, filed Oct. 17, 2006, and is a 371 ofPCT Application PCT/US07/21976, filed Oct. 15, 2007, the entire contentsof which are incorporated herein.

FIELD OF THE DISCLOSURE

The present disclosure relates to elastomers, a process for preparationof the elastomers, and uses of the elastomers, particularly in theproduction of cores of golf balls and in rubber formulations.

BACKGROUND OF THE DISCLOSURE

Golf ball cores are generally made using an elastomeric polybutadienethat may be crosslinked. Typically the polybutadiene is a nonfunctionalpolymer and will have little interaction with other compounds that makeup the core of the golf ball. A conventional polymer for use as the coreof a golf ball is a medium or high cis 1,4-polybutadiene containingbranching and/or 1,2 vinyl groups. In many cases the polybutadiene isprepared by anionic or transition metal (Ziegler-Natta) typepolymerization systems.

In other instances the polybutadiene is crosslinked with natural rubberor other elastomers. Other types of elastomers may include neoprene,polyisoprene, and ethylene-propylene diene monomer and combinationsthereof. As for the crosslinking agents, zinc diacrylate and peroxideare crosslinking agents for golf ball applications. Finally, othercompounds such as fillers or processing aids may be compounded into therubber formulation to form the core of the golf ball.

There is a continuing need for elastomers that are expected to be equal,and perhaps more effective in the production of golf ball cores.

SUMMARY OF THE DISCLOSURE

The present disclosure, in a first embodiment, relates to novelelastomeric interpolymers comprised of at least two different cyclicolefin monomers, which interpolymers are prepared by ring openingmetathesis polymerization process (ROMP), and which interpolymers arecharacterized as being non-crystalline as measured by the DSC techniquedescribed herein, have a glass transition temperature (T_(g)) of lessthan about −80° C., and have a number average molecular weight (M_(n))of at least 40 kg/mole.

In another embodiment, the present disclosure relates to a novel methodfor preparing the present non-crystalline cyclic olefin interpolymersthat comprises using a ring opening metathesis polymerization (ROMP)process, that includes a ring opening metathesis catalyst, and apolymerization terminator.

In another embodiment, the novel cyclic olefin interpolymers, which areinterpolymers of at least two cyclic olefins, comprise at least onefunctional group.

In another embodiment, the present disclosure relates to uses of thenovel interpolymers in the production of rubber compounds, tires, golfballs, cores of golf balls, and the like.

In another embodiment, the present disclosure relates to novel rubbercompounds and novel golf balls and cores of golf balls that utilizeelastomeric interpolymers comprised of at least two different cyclicolefin monomers, which interpolymers are prepared by ring openingmetathesis polymerization process (ROMP), and which interpolymers arecharacterized as having an amount of crystallinity ranging from 0 toabout 30% in one embodiment, and in other embodiments, from 0 to 25%,from 0 to about 20%, from 0 to about 10%, from 0 to about 5%, from 0 toabout 2%, and 0%, as measured by DSC technique described herein, have aglass transition temperature (T_(g)) of less than about −80° C., andhave a number average molecular weight (M_(n)) of at least 40 kg/mole.These interpolymers may be prepared by using a ring opening metathesispolymerization (ROMP) process, that includes a ring opening metathesiscatalyst, and a polymerization terminator.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present disclosure, in a first embodiment, relates to novelelastomeric interpolymers comprised of at least two different cyclicolefin monomers, which interpolymers are prepared by ring openingmetathesis polymerization (ROMP) process, and which interpolymers arecharacterized as being non-crystalline as measured by the DSC techniquedescribed herein, have a glass transition temperature (T_(g)) of lessthan about −80° C., and have a number average molecular weight (M_(n))of at least 40 kg/mole.

In another embodiment, the present disclosure relates to a novel methodfor preparing the non-crystalline cyclic olefin interpolymers thatcomprises using a ring opening metathesis polymerization (ROMP) process,that includes a ring opening metathesis catalyst, and a polymerizationterminator. The novel method for preparing the non-crystalline cyclicolefin interpolymers requires that at least one of the cyclic olefinmonomers be present in an amount of about 15 to about 85 mole %, and theremaining amount of about 85 to about 15 mole % comprise the othercyclic olefin monomer(s).

In another embodiment, the novel non-crystalline cyclic olefininterpolymers, which are interpolymers of at least two cyclic olefins,comprise at least one functional group.

In another embodiment, the present disclosure relates to uses of thenovel interpolymers in the production of rubber compounds, tires, golfballs, cores of golf balls, and the like.

In another embodiment, the present disclosure relates to novel rubbercompounds and novel golf balls and cores of golf balls that utilizeelastomeric interpolymers comprised of at least two different cyclicolefin monomers, which interpolymers are prepared by ring openingmetathesis polymerization process (ROMP), and which interpolymers arecharacterized as having an amount of crystallinity ranging from 0 toabout 30% in one embodiment, and in other embodiments, from 0 to 25%,from 0 to about 20%, from 0 to about 10%, from 0 to about 5%, from 0 toabout 2%, and 0%, as measured by DSC technique described herein, have aglass transition temperature (T_(g)) of less than about −80° C., andhave a number average molecular weight (M_(n)) of at least 40 kg/mole.These interpolymers may be prepared by using a ring opening metathesispolymerization (ROMP) process, that includes a ring opening metathesiscatalyst, and a polymerization terminator.

In more detail, the novel elastomeric interpolymers of the presentdisclosure comprise interpolymers of at least two, or more, differentcyclic olefin monomers. The two or more different cyclic olefin monomersare interpolymerized by ring opening metathesis polymerization. Thenovel resultant interpolymers of the ring opening metathesispolymerization (ROMP) are characterized by having no crystallinity (noncrystalline), having a glass transition temperature (T_(g)) of less thanabout −80° C., and a number average molecular weight (M_(n)) of at leastabout 40 kg/mole. In another embodiment, the glass transitiontemperature (T_(g)) may range from about −80° C. to about −130° C., andin yet another embodiment, from about −90° C. to about −120° C. Inanother embodiment, the number average molecular weight (M_(n)) may varyfrom at least about 40 kg/mole to about 500 kg/mole, in anotherembodiment from about 60 kg/mole to about 200 kg/mole, in anotherembodiment from about 60 kg/mole to about 150 kg/mole, and in yetanother embodiment, from about 40 kg/mole to about 100 kg/mole. Thedetermination of the non-crystalline property of the interpolymersherein is achieved by differential scanning calorimetry (DSC).

In preparing the interpolymers, any two or more, different cyclic olefinmonomers that may undergo ring opening metathesis polymerization may beused. Types of cyclic olefins which may be used include, but are notlimited to, cyclic alkenes; cyclic dienes, cyclic trienes, cyclicpolyenes, and combinations thereof. Specific examples of monomers thatmay be used, include but are not limited to, cyclopropene, cyclobutene,benzocyclobutene, cyclopentene, dicyclopentadiene, norbornene,norbornadiene, cycloheptene, cyclooctene, 7-oxanorbornene,7-oxanorbornadiene, cyclodecene, 1,3-cyclooctadiene, 1,5-cyclooctadiene,1,3-cycloheptadiene, [2.2.1]bicycloheptenes, [2.2.2]bicyclooctenes,cyclohexenylnorbornenes, norbornene dicarboxylic anhydrides,cyclododecene, 1,5,9-cyclododecatriene, derivatives thereof, and thelike, and combinations thereof.

In another embodiment, the novel interpolymers herein having nocrystallinity, may comprise at least one or more functional groups. Inanother embodiment, the interpolymer comprises at least two functionalgroups. In another embodiment, the at least one functional group may belocated at a terminal end of the interpolymer. In another embodiment,the functional group may be a pendant group. Where the interpolymer ismultifunctional, the functional groups may be located in any combinationof the terminal end(s) and/or pendant group(s) of the interpolymer. Inanother embodiment, the functional group may be an ionic group, and in afurther embodiment, a functional group that is capable of forming ionicbonds with a metal oxide, preferably a metal oxide used as filler in agolf ball core rubber formulation. An example of such a functional groupis a carboxylic acid group. Examples of other suitable functional groupsinclude amides, amines, esters, sulfonates, succinic anhydride, hydroxygroups, nitriles, and metal salts of carboxylic acids. In the case of amultifunctional interpolymer, the aforementioned functional groups maybe present in any combination thereof. Hydroxy groups are used herein todescribe an —OH grouping as well as a grouping in which the H atom hasbeen replaced by one or more atoms.

In an embodiment, the novel interpolymers herein having no crystallinityhave a number average molecular weight (M_(n)) of at least about 40kg/mole. In another embodiment, the average molecular weight (M_(n)) ofthe interpolymers ranges from about 40 kg/mole to about 500 kg/mole, inanother embodiment, from about 60 kg/mole to about 200 kg/mole, inanother embodiment, from about 60 kg/mole to about 150 kg/mole, and inanother embodiment, from about 40 kg/mole to about 100 kg/mole. Inanother embodiment, the M_(n) is at least about 49 kg/mole; in anotherembodiment, at least about 75 kg/mole; in another embodiment, at leastabout 100 kg/mole; and in another embodiment, at least about 110kg/mole. The M_(n) is determined using standard GPC techniques usinguniversal calibration with the appropriate Mark-Houwink constants. TheGPC procedure is described in detail herein.

The relative amounts of the two or more cyclic olefin monomerscomprising the novel interpolymers may be varied. Any amounts may beused provided that the resulting interpolymer is non-crystalline. Theamounts will be a function of the end purpose for which the interpolymeris to be used. For example, in a particular embodiment a copolymer,comprises a ratio of monomer units ranging from about 3.0:1.0 to about1.0:3.0, and in another embodiment, from about 2.0:1.0 to about 1.0:2.0,and in yet another embodiment, from about 1.5:1.0 to about 1.0:1.5, andfurther from about 1.0:1.0.

In another embodiment of the present disclosure, there is provided aprocess for producing the interpolymers herein having no crystallinitycomprising at least two or more cyclic olefin monomers. The methodcomprises ring opening metathesis polymerization of at least two, ormore, cyclic olefin monomers in the presence of a ring openingmetathesis polymerization catalyst, and terminating the ring openingmetathesis polymerization (ROMP). Any cyclic olefin monomer that canparticipate in a ROMP reaction may be used. Examples of suitable cyclicolefin monomers have been described herein. The novel method forpreparing the non-crystalline cyclic olefin interpolymers requires thatat least one of the cyclic olefin monomers be present in an amount ofabout 15 to about 85 mole %, and the remaining amount of about 85 toabout 15 mole % comprise the other cyclic olefin monomer(s).

In a typical ROMP, cyclic olefin monomers capable of undergoing ringopening metathesis polymerization were mixed in a reaction vessel andcontacted with a ROMP metathesis catalyst while stirring at atemperature range at which the ROMP metathesis reaction occurs. Thereaction is optionally performed in the presence of a solvent. If asolvent is utilized, the concentration of the monomers is above theequilibrium monomer concentration. The reaction is continued until thedesired level of monomer conversion and molecular weight range isachieved or until the monomer concentration is below the equilibriummonomer concentration. At this point, catalyst deactivation is inducedand the reaction is terminated. The polymer produced is then removedfrom the reaction vessel.

In respect of the ROMP process herein, the equilibrium monomerconcentration is the monomer concentration below which no furtherpolymerization occurs at a given temperature. Furthermore, thedeactivation of the catalyst may be induced by use of a catalystdeactivator, which is a moiety that terminates the activity of acatalytic species when placed in contact with the catalytic species. Forfurther information, ROMP is described in K. J. Ivin and J. C. Mol,Olefin Metathesis and Metathesis Polymerization, Chap. 11 (1997), whichis hereby incorporated by reference.

Any ring opening metathesis polymerization catalyst may be used toinitiate the ring opening metathesis polymerization. Suitable types ofROMP metathesis catalysts include an in-situ catalyst, a supportedmetathesis catalyst, and a single-site catalyst. An example of anin-situ catalyst is the reaction product of a transition metal halideand an alkyl compound that includes an IUPAC Group IIIB element, e.g.,B, Al, Ga, In, and Tl. For more background on in-situ catalysts,incorporated herein by reference is K. J. Ivin and J. C. Mol, OlefinMetathesis and Metathesis Polymerization, Chap. 2 (1997).

In respect of the ROMP process, supported metathesis catalysts suitablefor ring opening metathesis polymerization are well known. In detail, asupported ROMP metathesis catalyst is any type of ROMP catalyst that ischemically bound to or physically impregnated in a support materialsubstrate and is capable of initiating a metathesis reaction. Examplesof support materials include porous materials such as talc, inorganicoxides, inorganic chlorides, and resinous materials such as polyolefinor polymeric compounds. For further information on supported ROMPmetathesis catalysts, reference is made to K. J. Irvin, J. C. Mol OlefinMetathesis and Metathesis Polymerization (Chapter 2) and R. H. Grubbs(ed) Handbook of Metathesis Vol. 2, Chap. 2.10, which are incorporatedherein by reference in their entirety. Examples of supported metathesiscatalysts include crosslinked polystyrene bound ruthenium metal carbenesand thermally activated molybdenum oxide impregnated in alumina.

With further respect to the ROMP process, there may be used as acatalyst, any single-site catalyst that is suitable for the ring openingmetathesis polymerization of the cyclic olefin monomers to be achieved.In detail, a single-site catalyst may be described as a catalyst solelycomposed of one molecular species which contains a well-defined singlecatalytic site. The single-site catalysts for the ROMP process arewell-known.

Examples of single-site ROMP process catalysts are referred to asGrubbs-type catalysts and Schrock-type catalysts. The Grubbs-type andthe Schrock-type catalysts are well-known catalysts.

In more detail, Grubbs-type catalysts are single-site transition metalcomplex catalysts that are capable of initiating a ROMP metathesisreaction. Key structural features of Grubbs catalysts are the presenceof an active carbene metal-carbon double bond and an electron-rich, lowoxidation state transition metal center atom such as ruthenium orosmium.

Schrock-type catalysts are a class of single-site transition metalcomplexes capable of initiating a metathesis reaction. Key structuralfeatures of Schrock catalysts are the presence of an active alkylidenemetal-carbon double bond and an electron-deficient, high oxidation stateearly transition metal center atom such as tungsten or molybdenum.

For more information on Schrock-type catalysts, reference is made to R.R. Schrock Agnew. Chem. Int. Ed. (2006), 45, 3748. “MultipleMetal-Carbon Bonds for Catalytic Metathesis Reactions,” the content ofwhich is hereby incorporated by reference.

For more information on Grubbs-type catalysts, reference is made to R.H. Grubbs Agnew. Chem. Int. Ed. (2006) 45, 3760. “Olefin-metathesisCatalysts for the Preparation of Molecules and Materials,” the contentsof which are incorporated herein by reference.

In one or more embodiments, the ROMP catalyst includes a ruthenium-basedor osmium-based ROMP catalyst. Any ruthenium-based or osmium-based ROMPcatalyst that is effective for ring-opening metathesis polymerization(ROMP) reactions can be used.

The ROMP method may include isolating the interpolymer. Exemplarytechniques, which may be used to isolate the interpolymer, include steamdesolventizing the interpolymer, drum drying, or coagulating theinterpolymer in a suitable non-solvent material such as isopropanol, ordistillation of solvent or unreacted monomer.

The ROMP method may also be used to produce interpolymers containing oneor more functional groups on the chain terminus, on the polymerbackbone, or as a pendant group. In one embodiment, the functionalizedinterpolymer is formed from the ring opening metathesis polymerizationof a mixture of cyclic olefin monomers wherein at least one monomercontains an integral functional group. In another embodiment, thefunctionalized interpolymer is formed from the ring opening metathesispolymerization of a mixture of cyclic olefin monomers and an additivealkene containing a functional group. It is also possible to add atleast one functional group to the polymer chain along the backbone or atthe chain end after the ROMP reaction is complete. In one embodiment,maleic anhydride is added to the polymer chain, producing a succinicanhydride group.

In carrying out the ROMP process for producing the interpolymers, it ispossible to introduce additives to control the molecular weight and/orplace functionality on the ends of the interpolymer chains. In oneembodiment, the additive is trans-β-hydromuconic acid or the like.

Examples of solvents that can be used in the ROMP include, but are notlimited to, organic solvents that are inert under the ROMP conditions.Suitable solvents include aromatic hydrocarbons, chlorinatedhydrocarbons, ethers, aliphatic hydrocarbons, alcohols, ketones, ormixtures thereof. Examples of useful solvents include benzene, toluene,p-xylene, methylene chloride, dichloroethane, dichlorobenzene,tetrahydrofuran, chloroform, n-hexane, cyclohexane, hexane isomers,heptane, diethyl ether, pentane, or mixtures thereof. In one embodiment,the solvent may be purified by degassing with an inert atmosphere. Ifdesired, the solvent may be dried.

ROMP reactions occur over a wide range of temperatures. In oneembodiment, the ROMP reaction may be carried out at a temperatureranging from about minus 50° C. to the ceiling temperature of the cyclicolefin monomer mixture. In another embodiment, the temperature rangesfrom minus 40° C. to about 120° C.

ROMP reactions typically occur at temperatures that are at or below theceiling temperature of the olefin monomer having the lowest ceilingtemperature. The ceiling temperature is the temperature above which aspecific polymer cannot exist. At the ceiling temperature, the rate ofdepolymerization is the same as the rate of polymerization.

Any amount of catalyst may be used that allows the ROMP to be achieved,and the interpolymer to be prepared. In one embodiment, the amount ofcatalyst used is about 0.0001 mole catalyst to about 10 moles ofcatalyst per 100 moles of monomer.

The order in which the reactants are combined in the ROMP is notlimited. In one embodiment, the olefin monomers are combined to form amixture, and then the ROMP catalyst is added to the mixture.

The progress of the ROMP reaction can be monitored by standardtechniques, e.g. gas chromatography, liquid chromatography, HPLC,nuclear magnetic resonance spectroscopy and % total solids analysis. Inone embodiment, the reaction is terminated by adding a catalystdeactivator, that reacts with the ROMP catalyst, such as ethyl vinylether.

The ROMP process for preparing the interpolymers may be carried outcontinuously, semi-continuously or batchwise.

All of the above description concerning the ROMP process, except for useof the specified amounts of the cyclic olefin monomers described hereinthat result in the preparation of non-crystalline elastomericinterpolymers, is applicable to the preparation of metathesiselastomeric interpolymers that have a crystallinity level ranging fromgreater than 0% to about 30%.

In preparing rubber compositions herein, incorporating any of the cyclicolefin interpolymers having crystallinity ranging from 0 to about 30%,any rubber may be used. Suitable rubbers include, but are not limitedto, any natural rubbers, synthetic rubbers and mixtures thereof. Thesynthetic elastomers typically derive from the polymerization ofconjugated diene monomers. These conjugated diene monomers may becopolymerized with other monomers such as vinyl aromatic monomers. Otherrubbery elastomers may derive from the polymerization of ethylenetogether with one or more alpha-olefins and optionally one or more dienemonomers.

Useful rubbery elastomers include natural rubber, syntheticpolyisoprene, polybutadiene, polyisobutylene-co-isoprene, neoprene,poly(ethylene-co-propylene), poly(styrene-co-butadiene),poly(styrene-co-isoprene), poly(styrene-co-isoprene-co-butadiene),poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene),polysulfide rubber, acrylic rubber, urethane rubber, silicone rubber,epichlorohydrin rubber, and mixtures thereof. These elastomers can havea myriad of macromolecular structures including linear, branched andstar shaped. In one embodiment, elastomers include natural rubber,isoprene, styrene-butadiene copolymers, and butadiene rubber, andmixtures thereof, as a result of their common usage in the tireindustry.

The rubber compositions and golf ball core compositions herein may beprepared in accordance with any process known in the art. For example,the rubber compositions may be compounded or blended using mixingequipment and procedures conventionally employed in the art, such askneaders, roll mills, and extruders.

The rubber compositions may comprise further ingredients that are knownand conventional in the rubber compositions, such as fillers andadditive materials such as, but not limited to, curing agents (for ageneral disclosure of suitable vulcanizing agents one can refer toKirk-Othmer, Encyclopedia of Chemical Technology, 3^(rd) ed., WileyInterscience, N.Y. 1982, Vol. 20, pp. 365-468, particularly“Vulcanization Agents and Auxiliary Materials” pp. 390-402), activators,retarders and accelerators; processing additives, such as oils; resins,including tackifying resins; plasticizers; pigments; additional fillers,fatty acids; zinc oxide; waxes; antioxidants; antiozonants; peptizingagents; and the like. As known to those skilled in the art, theadditives mentioned above are selected and commonly used in conventionalamounts. For example, without limitation, a tire component compoundtypically contains elastomers, fillers, processing oils/aids,antidegradants, zinc oxide, stearic aid, sulfur, accelerators andcoupling agents. Such compounds can have such additional ingredients inthe following amounts:

Fillers: from about 0 to about 150 phr, and in another embodiment, fromabout 30 to about 80 phr;

Processing oils/aids: from about 0 to about 75 phr, and in anotherembodiment, from about 0 to about 40 phr;

Antidegradants: from about 0 to about 10 phr, and in another embodiment,from about 0 to about 5 phr;

Stearic acid: from about 0 to about 5 phr, and in another embodiment,from about 0 to about 3 phr;

Zinc oxide: from about 0 to about 10 phr, and in another embodiment,from about 0 to about 30 phr;

Sulfur: from about 0 to about 10 phr, and in another embodiment, fromabout 0 to about 5 phr; and

Coupling agent: from about 0 to about 30 phr, and in another embodiment,from about 5 to about 15 phr.

Fillers that may be used include carbon black, fumed silica, colloidalsilica, silica, alumina, aluminum hydroxide, magnesium hydroxide, clays(hydrated aluminum silicates) and starch.

Processing aids commonly include a broad category of substances thatimprove various aspects of the process of forming vulcanizablecompositions and vulcanizates. For example, processing aids may preventfiller agglomeration and reduce viscosity.

Certain additional fillers can be utilized as processing aids, includingclay (hydrous aluminum silicate), talc (hydrous magnesium silicate),aluminum hydrate, mica, and sodium sulfate. In one embodiment, micasprincipally containing alumina and silica are used.

Rubber curing agents may be employed, including sulfur or peroxide-basedcuring systems. Curing agents are described in Kirk-Othmer, Encyclopediaof Chemical Technology, Vol. 20, pp. 365-468, (3^(rd) Ed. 1982),particularly Vulcanization Agents and Auxiliary Materials, 390-402, andA. Y. Coran, Vulcanization in Encyclopedia of Polymer Science andEngineering (2^(nd) Ed. 1989), which are incorporated herein byreference. Vulcanizing agents may be used alone or in combination.

Accelerators that may be used suitably include thiazoles,dithiocarbamates, dithiophosphates, guanidines, sulfenamides,sulfenimides, and thiurams. Specific examples include2-mercaptobenzothiazole, 2,2′-dithiobis(benzothiazole),N-cyclohexyl-2-benzothiazole-sulfenamide (CBS),N-tert-butyl-2-benzothiazole sulfenamide (TBBS), and1,3-diphenylguanidine.

Oils, waxes, scorch inhibiting agents, tackifying resins, reinforcingresins, fatty acids, peptizers, and zinc oxide may also be employed.

In preparing the rubber compositions, in one embodiment, an initialmasterbatch is prepared that includes the rubber component and thereinforcing fillers, as well as other optional non-curative additives,such as processing oil, antioxidants, and the like. After themasterbatch is prepared, one or more optional remill stages can followin which either no ingredients are added to the first mixture, or theremainder of the non-curing ingredients are added, in one embodiment, toreduce the compound viscosity and improve the dispersion of thereinforcing filler. The final step of the mixing process is the additionof vulcanizing agents to the mixture.

In more detail concerning the masterbatch process, the vulcanizablerubber composition may be prepared by forming an initial masterbatchcomposition that includes elastomer and other ingredients. To preventpremature vulcanization, this initial composition generally excludes anyvulcanizing agents.

Once the initial masterbatch composition is processed, the vulcanizingagents may be introduced and blended into the initial masterbatch toform a final mix. Additional ingredients, such as accelerators, may beadded to the final mix during this stage. The final mix in oneembodiment, is prepared at low temperatures that do not initiate thevulcanization process.

In respect of golf ball formulations and systems, the following isappropriate. The typical cure systems used in golf ball cores consist ofa free radical initiator such as organic peroxides, a metal saltcrosslinking agent and a co-curing agent such as unsaturated organicimides or multifunctional monomers such as triallyl cyanurate. Examplesof the metal salt crosslinking agents include zinc and magnesiumdiacrylates and dimethacrylates. Co-curing agents such as triallylcyanurate, triallyl isocyanurate and N,N-m-phenylene dimaleimide areavailable for use. Peroxide initiators, such as dicumyl peroxide areavailable for use.

In preparing cores of golf balls and golf balls, the elastomericinterpolymers described herein that are prepared by ROMP may beutilized.

Suitable for use in preparing cores for golf balls and golf balls, areelastomeric interpolymers comprising at least two cyclic olefinmonomers, wherein the interpolymer is prepared by a ring openingmetathesis polymerization of the at least two cyclic olefin monomers,and wherein the interpolymer is characterized by having nocrystallinity, a glass transition temperature (T_(g)) of less than −80°C. and a number average molecular weight (M_(n)) of at least 40 kg/mole,each of the properties determined by the test procedures describedherein. With respect to these interpolymers, the T_(g) may range fromabout −80° C. to about −130° C. in one embodiment, and in anotherembodiment, from about −90° C. to about −120° C. Further, the M_(n) mayvary from at least 40 kg/mole to about 500 kg/mole, in one embodiment,and in other embodiments, from about 60 to about 200 kg/mole, and fromabout 60 to about 150 kg/mole.

Also suitable for use in preparing cores for golf balls and golf ballsare elastomeric interpolymers comprising at least two cyclic olefinmonomers, wherein the interpolymer is prepared by a ring openingmetathesis polymerization of the at least two cyclic olefin monomers,and wherein the interpolymer is characterized by having a crystallinityranging from 0 to about 30% in one embodiment, and in other embodiments,from 0 to 25%, from 0 to about 20%, from 0 to about 10%, from 0 to about5%, from 0 to about 2%, and 0%, a glass transition temperature (T_(g))of less than −80° C., and a number average molecular weight (M_(n)) ofat least 40 kg/mole, each of the properties determined by the testprocedures described herein. With respect to these interpolymers, theT_(g) may range from about −80° C. to about in one embodiment, and inanother embodiment, from about −90° C. to about −120° C. Further, theM_(n) may vary from at least 40 kg/mole to about 500 kg/mole, in oneembodiment, and in other embodiments, from about 60 to about 200kg/mole, and from about 60 to about 150 kg/mole. In addition, in oneembodiment, the crystallinity may vary from greater than 0 to about 30%in one embodiment, and in other embodiments, from 0 to 25%, from 0 toabout 20%, from 0 to about 10%, from 0 to about 5%, from 0 to about 2%,and 0%.

It is expected that the metathesis prepared interpolymers herein whetherhaving or not having crystallinity, will have a suitable balance ofdynamic stiffness and hysteresis. It is further expected that thepresent metathesis prepared interpolymers whether having or not havingcrystallinity, will have a satisfactory balance of coefficient ofrestitution and compression response properties such that a useful golfball core and golf ball may be produced. The present interpolymerswhether having crystallinity or not having crystallinity, are expectedto also have applications in the areas of rubber for tires as well asplastics or other types of rubber compounds. Particular plastics ofinterest include ABS and HIPS.

The following examples are presented to illustrate the presentdisclosure and to assist one of ordinary skill in making and using thesame. The examples are not intended in any way to otherwise limit thescope of the disclosure.

EXAMPLES Test Procedures

CRYSTALLINITY AND GLASS TRANSITION TEMPERATURE (T_(g))—The degree ofcrystallinity of the interpolymers produced herein by the ROMP of thecyclic olefin monomers is determined as follows. The glass transitiontemperature (T_(g)) of the interpolymers produced herein by the ROMP ofcyclic olefin monomers is determined as follows:

Thermal properties of the interpolymers were measured by conventionaldifferential scanning calorimetry (DSC). Using a TA Instruments DSC2910, a 10 mg sample of the interpolymer is cooled from room temperatureto −150° C., at a cooling rate of 10° C./minute, and then heated to 100°C. at a rate of 10° C./minute. The heat flow data, collected during theheating scan, were used to assess thermal transitions of theinterpolymer.

Polymers which have sufficient chain stereoregularity can crystallize attemperatures between the glass transition temperature and the meltingtemperature. Unlike low molecular weight organic liquids, however,complete crystallization is never possible and hence crystallizablepolymers are considered semi-crystalline materials with typical levelsof crystallinity ranging from 15% to 70% as determined using standarddifferential scanning calorimetry (DSC) techniques. As is commonlyknown, the percent crystallinity (X_(c)) can be evaluated by DSC fromthe area of the endothermic melting peak (A), which is integratedrelative to the underlying heat flow baseline, by dividing this area bytabulated heat of fusion (ΔH_(f)) for the polymer of interest. This isindicated in the equation below:Xc=100*A/ΔH _(f)Both A and ΔH_(f) are in units of J/g and X_(c) is expressed in %For the polymers claimed herein, the reported heat of fusion forcis-1,4-polybutadiene is the most appropriate known value for percentcrystallinity determination. This value is 170.4 J/g [L. Mandelkern andR. G. Alamo, “Thermodynamic Quantities Governing Melting”, in J. E.Mark, ed., Physical Properties of Polymers Handbook (AIP Press:Woodbury, N.Y., 1996).

In determining the crystallinity level of the interpolymer, it isunderstood that an interpolymer is considered to be non-crystalline ifthe interpolymer does not display an endothermic melting transition attemperatures above the glass transition temperature (T_(g)) when usingthe above DSC technique. In other words, X_(c)=0 for non-crystallineinterpolymers. There is a step change in the heat flow versustemperature response at the glass transition. The glass transitiontemperature (T_(g)) is defined as the temperature corresponding to themidpoint in the endothermic step in heat flow in accordance withstandard practice.

NUMBER AVERAGE MOLECULAR WEIGHT (M_(n))—The number average molecularweight (M_(n)) of the interpolymers produced herein by the ROMP ofcyclic monomers is determined by the following procedure:

Gel permeation chromatography (GPC) was performed in tetrahydrofuransolvent using a Waters Model 150-C with a refractive index detector. GPCmeasurements were conducted relative to polystyrene standards, and theresults were then converted into numerical molecular weight data byapplying the universal calibration approach using data from themolecular weight dependence of intrinsic viscosity. The Mark-Houwinkconstants for cis-1,4-polybutadiene were used for the universalcalibration. The number average molecular weight (M_(n)) and weightaverage molecular weight (M_(w)) were determined from the molecularweight distribution based on the well-known definitions of theseaverages.

COMPRESSION TEST—PGA compression is determined by placing a golf ball inan apparatus which has the form of a small press with an upper and loweranvil. The upper anvil is at rest against a 200 pound (90.7 kg) springdie, and the lower anvil has a range of linear travel of about 0.300inches (7.6 mm) by means of a crank mechanism. In its open position, thegap between the anvils is sufficient to allow a clearance of at least0.100 (2.5 mm) inches after insertion of the test ball. As the loweranvil is raised by the crank and the gap is closed, the apparatusapplies compressive force and presses the ball against the spring loadedupper anvil. When the equilibrium point of the spring is reached, thedeflection of the upper anvil is measured with a micrometer. Whentesting a ball where deflection of the upper anvil is 0.200 inches, (5.1mm) the ball will be regarded as having a PGA compression of “0.” Inpractice, tournament quality balls have compression ratings about 50 to100 which means that the upper anvil was deflected a total of 0.150inches (3.8 mm) to 0.100 inches (2.5 mm). The compression device ismanufactured by O K Automation of Sinking Spring, Pa.

COEFFICIENT OF RESTITUTION (COR):—The coefficient of restitution is theratio of the inbound velocity vs. outbound velocity of a golf ball (orcore) measured by firing the core from an air cannon at speeds from 100to 144 ft. per second (30.5 to 45.7 meters/second). The ball reboundsfrom a thick solid steel plate and the two velocities are measuredelectronically. The machine is produced by Hye Precision Products,Perry, Ga.

Example 1

A batch mixture comprised of 1.3 kg (1.6 L) olefin free cyclohexane,0.75 kg (0.97 L, 11.0 moles) cyclopentene, and 0.51 kg (0.57 L, 3.1moles) 1,5,9-cyclododecatriene were charged into a 1-gallon volumereactor, purged with nitrogen, and stirred (49.5% solids). A solution of0.90 g of trans-β-hydromuconic acid (6.2 mmol) in 100 mL absoluteethanol was charged into the vessel and the reactor contents were heatedto 40° C. A solution composed of 0.21 g (0.25 mmol) Grubbs 2ndGeneration ruthenium ring opening metathesis polymerization catalyst in50 mL of degassed toluene was added to the reactor. Within 20 minutes,polymerization of the monomers began to occur, and a reactiontemperature increase to 43° C. was observed. The resulting product wasthen stirred at a constant 40° C. temperature for an additional 2 hours.At this time, 4 mL of ethyl vinyl ether was added to terminate thepolymerization. After stirring an additional 12 hours, the interpolymersolution was then coagulated into an isopropanol/BHT (butylated hydroxytoluene) mixture, producing a white, elastomeric solid material. Theresulting elastomeric interpolymer had the following characteristics:non crystalline; M_(n)=49.2 kg/mol; M_(w)/M_(n)=1.6; T_(g)=−97.7° C. Theinterpolymer composition was 45:55 mole percent butenyl:pentenyl units.The catalyst utilized in this example is referred to commercially as“Grubbs Second Generation Catalyst.” This catalyst is manufactured byMateria, Inc. (Pasadena, Calif. USA) and the catalyst is sold bySigma-Aldrich (St. Louis, Mo. USA). The chemical name of the catalyst is(1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium.

Example 2

A batch mixture comprised of 1.1 kg (1.4 L) deolefinated cyclohexane,0.73 kg (0.95 L, 10.9 moles) cyclopentene, and 0.51 kg (0.57, 3.1 moles)L 1,5,9-cyclododecatriene were charged into a 1-gallon volume reactor,purged with nitrogen, and stirred (52.6% solids). A solution of 0.90 gof trans-β-hydromuconic acid (6.2 mmol) in 100 mL absolute ethanol wascharged into the vessel and the reactor contents were heated to 55° C. Asolution composed of 0.49 g (0.6 mmol) Grubbs 2^(nd) Generationruthenium metathesis catalyst in 50 mL degassed toluene was added to thereactor. Within 10 minutes, polymerization of the monomer began tooccur, and a reaction temperature increase to 71° C. was observed. Theresulting polymer solution was then cooled to 40° C. and stirred for anadditional 2 hours. At this time, a solution of 5 mL of ethyl vinylether in 50 mL cyclohexene was added to terminate the polymerization.After stirring an additional 12 hours, the polymer was then isolated bycoagulation into an isopropanol/BHT (butylated hydroxy toluene) mixture,producing elastomeric solid material. The resulting polymer had thefollowing characteristics: M_(n)=58.5 kg/mol; M_(w)/M_(n)=1.67;T_(g)=−95.6° C., and was non-crystalline. The interpolymer compositionwas 53:47 percent butenyl:pentenyl units. The catalyst utilized in thisexample is referred to commercially as “Grubbs Second GenerationCatalyst.” This catalyst is manufactured by Materia, Inc. (Pasadena,Calif., USA) and the catalyst is sold by Sigma-Aldrich (St. Louis, Mo.USA). The chemical name of the catalyst is(1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium.

Example 3

The polymer of Example 1 was compounded and cured in a golf ball coreformulation. The formulation contained 100 parts per hundred rubber(phr) of polymer, 23 phr zinc diacrylate, 20 phr zinc oxide, 0.2 phrantioxidant (Ciba Irganox 1076), and 0.5 phr peroxide(t-butylperoxydiisopropyl-benzene; Vulcup R from Geo SpecialtyChemicals). All ingredients except the peroxide were mixed in a 300 grambatch in a Brabender Plasticorder internal mixer at a mixing speed of 60rpm for 5 minutes. The initial temperature was 75° C. and the finaltemperature of the batch was 105° C. The peroxide was subsequently addedto the compound using a two-roll mill at 60° C. Spherical cores withdiameters equal to 1.54 inches (39.1 mm) were formed from the finalmixture by curing in molds for 20 minutes at 160° C. The coefficient ofrestitution (COR) was determined for the cores using an air cannon. Inthis test, the cores have an initial velocity of approximately 143 feetper second (45.6 m/s) before impacting a steel plate. A compressionvalue of 34 and a COR of 0.68 were measured for this example.

Example 4

The polymer of Example 2 was compounded and cured in a golf ball coreformulation. The formulation contained 100 parts per hundred rubber(phr) of polymer, 23 phr zinc diacrylate, 20 phr zinc oxide, 0.2 phrantioxidant (Ciba Irganox 1076), and 0.5 phr peroxide(t-butylperoxydiisopropyl-benzene; Vulcup R from Geo SpecialtyChemicals). All ingredients except the peroxide were mixed in a 300 grambatch in a Brabender Plasticorder internal mixer at a mixing speed of 60rpm for 5 minutes. The initial temperature was 75° C. and the finaltemperature of the batch was 105° C. The peroxide was subsequently addedto the compound using a two-roll mill at 60° C. Spherical cores withdiameters equal to 1/54 inches (39.1 mm) were formed from the finalmixture by curing in molds for 20 minutes at 160° C. The coefficient ofrestitution (COR) was determined for the cores using an air cannon. Inthis test, the cores have an initial velocity of approximately 143 feetper second (45.6 m/s) before impacting a steel plate. A compressionvalue of 32 and a COR of 0.69 were measured for this example.

The exemplary embodiment has been described with reference to thepreferred embodiments. Obviously, modifications and alterations willoccur to others upon reading and understanding the preceding detaileddescription. It is intended that the exemplary embodiment be construedas including all such modifications and alterations insofar as they comewithin the scope of the appended claims or the equivalents thereof.

1. A core of a golf ball comprising an elastomeric interpolymer, whereinthe interpolymer is prepared by a ring opening metathesis polymerizationof at least two cyclic olefin monomers, and wherein the interpolymer ischaracterized by having a crystallinity of 0 to about 30%, a glasstransition temperature (T_(g)) of less than −80° C., and a numberaverage molecular weight (M_(n)) of at least 40 kg/mole, each of theproperties determined by the test procedures described herein, whereinthe at least two cyclic olefin monomers are selected from the groupconsisting of cyclopropene, cyclobutene, benzocyclobutene, cyclopentene,norbornene, norbornadiene, cycloheptene, cyclooctene, 7-oxanorbornene,7-oxanorbornadiene, cyclodecene, 1,3-cyclooctadiene, 1,5-cyclooctadiene,1,3-cycloheptadiene, [2.2.1]bicycloheptenes, [2.2.2]bicyclooctenes,cyclohexenylnorbornenes, norbornene dicarboxylic anhydrides,cyclododecene, 1,5,9-cyclododecatriene, and a mixture thereof.
 2. Thecore of a golf ball of claim 1 wherein the elastomeric interpolymer hasa crystallinity of 0%, a glass transition temperature (T_(g)) rangingfrom less than −80° C. to about −130° C., and has a number averagemolecular weight (M_(n)) ranging from at least 40 kg/mole to about 500kg/mole.
 3. The core of a golf ball of claim 1 wherein the interpolymerhas a glass transition temperature (Tg) ranging from less than −80° C.to about −130° C.
 4. The core of a golf ball of claim 1 wherein theinterpolymer has a number average molecular weight of at least 40kg/mole to about 500 kg/mole.
 5. The core of a golf ball of claim 1wherein the interpolymer has a crystallinity of 0 to about 20%.
 6. Thecore of a golf ball of claim 1 wherein the interpolymer has acrystallinity of 0%.
 7. The core of a golf ball of claim 1 wherein theinterpolymer has a crystallinity of 0%, a glass transition temperature(T_(g)) of less than −80° C. to about −130° C., and a number averagemolecular weight (M_(n)) of at least 40 kg/mole to about 200 kg/mole. 8.The core of a golf ball of claim 1, wherein said metathesispolymerization is effected with a Grubbs catalyst.
 9. The core of a golfball of claim 1, wherein said metathesis polymerization is effected aruthenium-based or osmium-based ROMP catalyst.
 10. The core of a golfball of claim 1, wherein the elastomeric interpolymer has at least onefunctional group.
 11. The core of a golf ball of claim 10, wherein theelastomeric interpolymer has at least one functional group, and the atleast one functional group is selected from the group consisting of acarboxylic acid, a nitrile, an amine, an amide, an ester, a sulfonate, ametal salt of a carboxylic acid, succinic anhydride, and a hydroxylgroup.
 12. The core of a golf ball of claim 11, where the functionalgroup is a carboxylic acid group or a metal salt of a carboxylic acid.